Sealing device with improved adhesion

ABSTRACT

The present invention relates to a sealing device ( 1 ) which comprises a barrier layer ( 2 ) with a thermoplastic polymer P1, and an adhesive layer ( 3 ) with at least one ethylene-vinyl acetate copolymer (EVA) P2 and azo-dicarbonamide A, and which is suitable for sealing bases in the building sector. The invention further relates to a method for sealing said bases. The method according to the invention allows structures of civil engineering to be sealed rapidly and efficiently and ensures good adhesion of the sealing device on the base.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application of InternationalApplication Serial No. PCT/EP2013/059412, filed on May 6, 2013, which inturn claims the benefit of EP 12183595.3, filed on Sep. 7, 2012, and CH00641/12, filed on May 7, 2012, and all of which are hereby incorporatedby reference in their entirety, for any and all purposes.

TECHNICAL FIELD

The invention relates to the field of sealing substrates and bases, inparticular in the construction field.

STATE OF THE ART

Substrates and bases that must be waterproofed, in particular concretestructures, can be found in large numbers in structural and civilengineering. Such substrates and bases are typically sealed by way ofbitumen sheets or mechanically attached plastic membranes. However, dueto their thermoplastic behavior, bitumen sheets are susceptible totemperature fluctuations. Elastic plastic membranes, in contrast,exhibit elastic behavior that is constant over a wide temperature rangeand thus fulfill their function as a seal even under extreme temperatureconditions. The combination of a plastic membrane with bitumen is notused due to numerous disadvantages. One problem, among other things, isthat a good adhesive bond between the plastic membrane in combinationwith bitumen and a substrate or a base must be present, which naturallyencompasses adhesion of all intermediate layers. The adhesion andcompatibility between the plastic sheet and bitumen in particular posesa problem that is very difficult to solve as a result of the materialsthat are involved.

This system moreover has the major disadvantage that high heat output isrequired to fully melt the bitumen, which typically necessitates the useof an open flame. This is not only expensive, but the high heat outputof such an open flame, which is difficult to control, can result insmoldering. Additionally, this system requires the plastic membrane, ifa plastic membrane is used, to be applied directly after the bitumen hasbeen melted, which makes positioning of the plastic membrane in advanceimpossible. Moreover, it is not possible to step on the base after thebitumen has been melted and before the sealing material is applied.

DESCRIPTION OF THE INVENTION

It is therefore the object of the present invention to provide a sealingdevice which does not have the disadvantages of the state of the art,and which in particular can be created and applied easily andefficiently and results in a good adhesive bond between the sealingdevice and the substrate or base. Moreover, a high level ofwaterproofing is to be ensured.

Surprisingly, it was found that this object can be achieved by a sealingdevice. Such a sealing device allows a substrate or a base, and moreparticularly a concrete structure, to be sealed quickly andcost-effectively.

It was further shown that the preferred embodiments can be used toeasily avoid an essential problem of the related art, namely that ofapplying the adhesive promoter, this being the bitumen, in a uniform andcontrolled manner, and that thus quality assurance in the creation of aseal can be considerably increased.

Another major advantage here is that the necessary adhesive promoter canbe distributed and fixed in a controlled manner on the sealing layer inan industrial process, and that this sealing layer can be used at theconstruction site ready-made with the adhesive promoter, namely anadhesive layer. In particular, it is advantageous that the use of masticasphalt can be dispensed with.

Moreover, such sealing devices can also be applied to a base withoutopen flame, which is in particular a safety advantage.

Another major advantage is the option of movably disposing the sealingdevice prior to the application to the base, due to the features of theadhesive layer. When provided in a suitable location, the sealing devicecan be firmly bonded to the base thereafter by heating the adhesivelayer.

Further aspects of the invention are the subject matter of furtherindependent claims. Particularly preferred embodiments of the inventionare the subject matter of the dependent claims.

Ways to Implement the Invention

In a first aspect, the present invention relates to a sealing device 1,comprising

-   -   a sealing layer 2, comprising a thermoplastic polymer P1,    -   and an adhesive layer 3, comprising        -   at least one ethylene-vinyl acetate copolymer (EVA) P2, and        -   azodicarbonamide A.

The sealing layer 2 is preferably bonded directly to the adhesive layer3. The expression “bonded directly” shall be understood to mean that nofurther layer or substance is present between two materials, and thatthe two materials are directly bonded to each other or adhere to eachother. The two materials can be present mixed with each other at thetransition between the two materials. The adhesive layer 3 can be bondedto the sealing layer 2 across the entire surface or discontinuously, inparticular across the entire surface.

FIG. 1 shows the composition of such a sealing device 1 comprising asealing layer 2 and an adhesive layer 3, where the sealing layer 2 isbonded directly to the adhesive layer 3.

If the sealing layer 2 is bonded directly to the adhesive layer 3, thisis advantageous insomuch as the sealing layer and the adhesive layer canthus be coextruded, for example, and moreover a good bond of the twolayers is ensured.

If the sealing layer 2 is bonded directly to the adhesive layer 3, it isparticularly advantageous if the sealing layer and the adhesive layerinclude polymers that are compatible with, and more particularly can behomogeneously mixed with, the polymers of the other layer.

For example, it is in particular advantageous if the thermoplasticpolymer P1 of the sealing layer 2 is polyethylene (PE) or a copolymer ofethylene and propylene.

It is further preferred if the sealing layer 2 comprises more than 40%by weight of the polymers P1 listed above as preferred polymers P1,based on the total weight of the sealing layer 2.

The sealing layer 2 particularly preferably comprises 70 to 100% byweight, in particular 90 to 100% by weight, and in particular 95 to 100%by weight of polymers P1 selected from the list consisting ofpolyethylene (PE) and copolymers of ethylene and propylene, based on thetotal weight of the polymers present in the sealing layer 2.

To be as suitable as possible as the sealing layer 2, it should be aswaterproof as possible and not decompose or be mechanically damaged evenunder the prolonged influence of water or moisture.

The sealing layer 2 comprises a thermoplastic polymer P1. Thethermoplastic polymer P1 is preferably thermoplastic polyolefins and/orpolyvinyl chloride (PVC).

The thermoplastic polymer P1 particularly preferably is a polymerselected from the group consisting of high-density polyethylene (HDPE),medium-density polyethylene (MDPE), low-density polyethylene (LDPE),polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET),polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), ethylenevinyl acetate (EVA), chlorosulfonated polyethylene, and polyolefin-basedthermoplastic elastomers (TPO).

Most preferably the thermoplastic polymer P1 of the sealing layer 2 ispolyethylene (PE) or a copolymer of ethylene and propylene.

In particular sheets as they are already used in the prior art forsealing purposes in structural and civil engineering are suited as thesealing layer. So as to be damaged or modified as little as possible byheating when the sealing device is applied to a base, it is particularlyadvantageous if the sealing layer are produced from a material having asoftening point of greater than 70° C., and preferably between 80° C.and 110° C. The sealing layer should advantageously have at least a lowdegree of elasticity, for example so as to be able to accommodatedifferences in expansion between the sealing device and the substrate orbase caused by temperatures, or stress caused by cracks in the base,without the sealing layer becoming damaged or tearing and impairing thesealing function of the sealing layer.

The sealing layer 2 preferably has a thickness of 0.1 to 10 mm, and moreparticularly of 1 to 5 mm.

The sealing layer 2 preferably includes a foamed portion 2 a on the sidefacing the adhesive layer 3. This is shown in FIG. 2, for example. Thisis advantageous inasmuch as lower heat input is required to heat theadhesive layer. Moreover, it is also possible to use heat sources forheating, the heat input of which is not as easy to control.

It is further advantageous if the thickness of the foamed portion of thesealing layer 2 a is 20 to 80%, and more particularly 45 to 65% of theentire thickness of the adhesive layer 2.

The density of the foamed portion of the sealing layer 2 a is preferably200 to 700 kg/m³, and more particularly 300 to 500 kg/m³.

The adhesive layer 3 comprises at least one ethylene-vinyl acetatecopolymer (EVA) P2.

The ethylene-vinyl acetate copolymer P2 preferably has a vinyl acetatecontent of 7 to 30% by weight, in particular 15 to 30% by weight,preferably 25 to 30% by weight. This contributes to good adhesion tosubstrates, in particular concrete.

Moreover, it can be advantageous if the content of azodicarbonamide A1is 0.1 to 15% by weight, in particular 0.5 to 5% by weight, particularlypreferably 0.5 to 3% by weight, most preferably 0.5 to 2% by weight,relative to the total weight of the sum of (ethylene-vinyl acetatecopolymer P2+azodicarbonamide A). This is beneficial for good adhesionto concrete.

It can also be advantageous if the content of azodicarbonamide A is 2 to10% by weight, in particular 4 to 8% by weight, particularly preferably4 to 6% by weight, relative to the total weight of the sum of(ethylene-vinyl acetate copolymer P2+azodicarbonamide A). Surprisingly,it was found that this results in particularly good adhesion to concretesurfaces which were pretreated with an epoxy resin-based primer.

Such epoxy resin-based primers have (before the curing) a free-flowingconsistency at room temperature and are typically applied to the base byway of brushing, spraying or pouring. It should be noted that the term“free-flowing” here shall be understood to include not only liquid, butalso honey-like to pasty materials having higher viscosities, the shapeof which conforms under the influence of the gravitational force of theearth.

These are in particular two-component epoxy resin compositions, and moreparticularly such in which the one (this being the first) componentincludes an epoxy resin, and more particularly an epoxy resin based onbisphenol A diglycidyl ether, and the other one (this being the second)component includes a curing agent, and more particularly polyamine orpolymercaptane. Moreover, the epoxy resin compositions areadvantageously low-viscosity compositions, and more particularly have aviscosity of less than 10,000 mPas, and preferably between 10 and 1,000mPas. Low-viscosity, two-component epoxy resin compositions as they aresold under the trade names Sikaprimer®, Sikafloor®, Sikagard® or SikaErgodur® by Sika Deutschland GmbH, or Sika Schweiz AG, are consideredparticularly preferred two-component epoxy resin compositions.

Moreover, it can be advantageous if the adhesive layer 3 comprises 0 to12% by weight, in particular 0 to 6% by weight, particularly preferably0 to 1% by weight, most preferably 0% by weight, relative to the totalweight of the adhesive layer, of a polymer P3, which is selected fromthe group consisting of:

-   -   maleic acid anhydride-functionalized polyethylene, in particular        maleic acid anhydride-functionalized LDPE or maleic acid        anhydride-functionalized HDPE (PE-MAH) and    -   maleic acid anhydride functionalized copolymer made of ethylene        and vinyl acetate (EVA-MAH).

This is beneficial for a good adhesion to concrete.

Moreover, it can also be advantageous if the adhesive layer 3 comprisesin addition a polymer P3, which is selected from the group consistingof:

-   -   maleic acid anhydride-functionalized polyethylene, in particular        maleic acid anhydride-functionalized LDPE or maleic acid        anhydride-functionalized HDPE (PE-MAH) and    -   maleic acid anhydride functionalized copolymer made of ethylene        and vinyl acetate (EVA-MAH).

It is preferable for the content of polymer P3 to be 4 to 17% by weight,in particular 12 to 16% by weight, relative to the total weight of thesum of (ethylene-vinyl acetate copolymer P2+polymer P3+azodicarbonamideA); and

the content of azodicarbonamide A is 2 to 6% by weight, in particular 4to 6% by weight, relative to the total weight of the sum of(ethylene-vinyl acetate copolymer P2+copolymer P3+azodicarbonamide A).

As a result, good adhesion to concrete surfaces which were pretreatedwith an epoxy resin-based primer is achieved.

It is further advantageous if the adhesive layer 3 includes <1% byweight, in particular 0 to 0.5% by weight, preferably 0 to 0.1% byweight, and most preferably no epoxy resin at all, based on the totalweight of the adhesive layer.

The term “epoxy resin” in the present document shall be understood tomean both solid epoxy resins and liquid epoxy resins.

This is beneficial, among other things, for improved adhesion, inparticular to concrete, and in particular to concrete treated in advancewith an epoxy resin primer. The adhesive layer 3 comprisesazodicarbonamide A.

So as to lower the activation temperature of azodicarbonamide (alsoreferred to as azobisformamide or diazenedicarboxylic acid diamide), forexample, it can be advantageous to add a catalyst, such as zinc oxide orurea, to the azodicarbonamide, typically in an amount of 10 to 50% byweight, based on the total weight of the azodicarbonamide A.

The adhesive layer 3 is preferably tack-free at 23° C. The term“tack-free” in connection with the adhesive layer 3 in the entirepresent document shall be understood to mean surface stickiness withinthe meaning of instant adhesion or tack, which is so low at 23° C. that,upon pressing a thumb with a pressure force of approximately 5 kg for 1second against the surface of the adhesive layer, the thumb does notstick to the surface of the adhesive layer, or the adhesive layer cannotbe lifted. In this way, the sealing device can be stored, transportedand processed more easily.

Particularly preferred are adhesive layers 3 comprising

70 to 99.5% by weight, in particular 80 to 99% by weight, preferably 90to 99% by weight,

ethylene-vinyl acetate copolymer P2, and

0.5 to 5% by weight, particularly preferably 0.5 to 3% by weight,preferably 0.5 to 2% by weight, azodicarbonamide A.

These adhesive layers preferably consist of more than 50% by weight, inparticular more than 70% by weight, in particular more than 80% byweight, preferably more than 90% by weight, most preferably more than98% by weight of the above-mentioned components P2 and A.

These adhesive layers preferably comprise 0 to 1% by weight, inparticular 0% by weight, relative to the total weight of the adhesivelayer, of a polymer P3, which is selected from the group consisting of:

-   -   maleic acid anhydride-functionalized polyethylene, in particular        maleic acid anhydride-functionalized LDPE or maleic acid        anhydride-functionalized HDPE (PE-MAH) and    -   maleic acid anhydride functionalized copolymer made of ethylene        and vinyl acetate (EVA-MAH).

Moreover, preferred are adhesive layers 3 comprising

70 to 98% by weight, in particular 80 to 96% by weight, preferably 90 to96% by weight, ethylene-vinyl acetate copolymer P2, and

2 to 10% by weight, particularly preferably 4 to 8% by weight,preferably 4 to 6% by weight, azodicarbonamide A.

It is preferable for the adhesive layers to comprise more than 50% byweight, in particular more than 70% by weight, in particular more than80% by weight, preferably more than 90% by weight, most preferably morethan 95% by weight, of the above-mentioned components P2 and A.

It is preferable for the adhesive layers to comprise 0 to 1% by weight,in particular 0% by weight, relative to the total weight of the adhesivelayer, of a polymer P3, which is selected from the group consisting of:

-   -   maleic acid anhydride-functionalized polyethylene, in particular        maleic acid anhydride-functionalized LDPE or maleic acid        anhydride-functionalized HDPE (PE-MAH) and    -   maleic acid anhydride functionalized copolymer made of ethylene        and vinyl acetate (EVA-MAH).

Moreover, preferred are adhesive layers 3 comprising

77 to 94% by weight, in particular 78 to 84% by weight, ethylene-vinylacetate copolymer P2, and

4 to 17% by weight, in particular 12 to 16% by weight, of a polymer P3,which is selected from the group consisting of

-   -   maleic acid anhydride-functionalized polyethylene, in particular        maleic acid anhydride-functionalized LDPE or maleic acid        anhydride-functionalized HDPE (PE-MAH) and    -   maleic acid anhydride functionalized copolymer made of ethylene        and vinyl acetate (EVA-MAH), and

2 to 6% by weight, in particular 4 to 6% by weight, azodicarbonamide A.

The adhesive layers preferably consist of more than 50% by weight, inparticular more than 70% by weight, in particular more than 80% byweight, preferably more than 90% by weight, of the above-mentionedcomponents P2, P3 and A.

It is further advantageous if the adhesive layer 3 has a thickness of0.05 to 0.5 mm, 0.1 to 0.3 mm.

The sealing layer 2 can preferably comprise an adhesive layer 3 on bothsides; this is shown in FIG. 3, for example. The sealing layer cancomprise one or two foamed portions, as is apparent as 2 a and 2 b inFIG. 3, or not.

It can further be advantageous if the sealing layer 2 comprises acarrier layer 9. The carrier layer 9 contributes to the dimensionalstability of the sealing layer. This is preferably a fiber material or amesh, in particular a fiber material. The term “fiber material” in theentire present document shall be understood to mean a material composedof fibers. The fibers comprise or consist of organic or syntheticmaterial. These are in particular cellulose fibers, cotton fibers,protein fibers, synthetic fibers or organic fibers, for example glassfibers. Preferably fibers made of polyester, or made of a homopolymer orcopolymer of ethylene and/or propylene, or made of viscose, shall beprimarily mentioned as synthetic fibers. The fibers can be short fibersor long fibers, spun, woven or unwoven fibers or filaments. The fiberscan moreover be aligned or drawn fibers. Moreover, it can beadvantageous to use different fibers, both in terms of geometry andcomposition, together.

The body composed of fibers can be produced using a wide variety ofmethods known to a person skilled in the art. In particular bodies thatare a woven fabric, laid scrim or knitted fabric are used. A felt ornonwoven fabric is particularly preferred as the fiber material.

The carrier layer is preferably incorporated into the sealing layer;moreover, it is advantageous if the carrier layer 9 comprisesintermediate spaces, which are at least partially interspersed with thematerial of the sealing layer 2. This is beneficial for a good bondbetween the sealing layer and the carrier layer.

It can moreover be advantageous if the sealing layer 2 comprises atopcoat 10, which is preferably applied to the side facing away from theadhesive layer 3. If the topcoat includes UV stabilizers, the topcoatcan protect the sealing device from aging by sunlight, for example. Ifthe topcoat includes color pigments, damage to the side of the sealingdevice which faces away from the adhesive layer, for example caused bythe transport or by the installation, can be discovered by the absenceof the topcoat at the damaged location.

A sealing device, the sealing layer of which comprises an incorporatedcarrier layer 9 and a topcoat 10, is shown in FIG. 4, for example.

It is further advantageous if the sealing device 1 is a flexiblemembrane, and more particularly a flexible sheet. This can be easilyrolled up and thus easily stored and/or transported. The sealing deviceis thus easy to take to the construction site and can be unrolled thereand cut to the required dimensions. This is a very cost- andtime-efficient work step.

A further aspect of the present invention relates to a method forsealing a substrate S1 4, comprising the following steps:

-   -   i) applying a sealing device 1, as it is described above, to a        substrate S1 4, wherein the adhesive layer 3 faces the substrate        S1 4; and    -   ii) heating the adhesive layer 3 of the sealing device 1,        preferably to a temperature of 80 to 600° C.

The substrate S1 4 is preferably a structural or civil engineeringstructure, which is to be sealed against moisture and water. Moreover,it can be the soil, a building, insulating material, or formwork. Thesubstrate S1 4 can be horizontal, or not.

The material of the substrate S1 is in particular wood, metal, a metalalloy, a mineral binding agent such as concrete or gypsum, plasticmaterial or thermal insulation material, such as foamed polyurethane,mineral wool or cellular glass (Foamglas). It is particularly preferredif the material is wood, metal, a metal alloy or concrete, in particularconcrete. The material is most preferably concrete, in particularconcrete.

The sealing device 1 can be applied to a substrate S1 4 in step i), forexample, by unrolling the sealing device or installing the sealingdevice across the entire surface. If the adhesive layer 3 is an adhesivelayer that is tack-free at 23° C., the sealing device can beconveniently (re)positioned on the substrate S1 until the heatingprocess in step ii).

Heating can take place in any arbitrary manner. Heating can be achievedby external or by internal heat sources, such as an exothermic chemicalreaction. The heating in step ii) is preferably carried out by way ofhot air, flame application, ultrasound, induction welding or an electricresistance heating element.

The adhesive layer 3 can be heated directly, for example by heating thesurface of the adhesive layer, in particular by way of hot air or flameapplication. Direct heating is also possible by way of an electricresistance heating element, for example an electric resistance heatingelement disposed in the adhesive layer, such as a metal mesh.

In addition or as an alternative, the adhesive layer 3 can also beheated indirectly, for example by heating the substrate S1, inparticular by way of hot air or flame application. However, thisrequires a substrate S1 that withstands such heat input without damage.Such heat input, however, typically necessitates higher heat input.

If the heating is carried out by way of flame application, it isadvantageous if the surface of the adhesive layer 3 is heated for 0.1 to30 seconds, in particular for 5 to 20 seconds, and preferably for 10 to15 seconds, to a temperature of 400° C. to 600° C., in particular to450° C. to 550° C., and in particular to 480° C. to 520° C.

The heating in step ii) can be carried out chronologically before and/orduring and/or after step i). If the heating in step ii) is carried outchronologically before step i), this typically take place shortly, inparticular within 30 seconds, and more particularly within 10 seconds,before the application in step i).

FIG. 5 shows a schematic cross-section through a substrate S1 4 to whichthe sealing device 1 is partially applied. Shown is the situation duringor after the heating in step ii). On the one hand, indirect heating byway of a heat source 6 is shown, wherein the heating is carried out byheating the substrate S1, typically by way of hot air or flameapplication. The arrows are intended to indicate the direction of theheat that is given off, proceeding from the heat source. On the otherhand, FIG. 5 also shows direct heating by way of a heat source, which istypically carried out by way of hot air or flame application. In thesituation shown in FIG. 5, the step i) of applying the sealing device 1and step ii) of heating the adhesive layer 3 essentially take placesimultaneously. After heating 3 a, the adhesive layer is firmly bondedto the substrate S1. Due to the roll shape of the sealing device, thesealing device can be unrolled after being initially positioned on thesubstrate S1 and steps i) and ii) can be carried out.

A further aspect of the present invention relates to a method forsealing a substrate S1′ 4, comprising the following steps:

-   -   i′) applying a sealing device 1, which comprises an adhesive        layer 3 on both sides, as it is described above, to a substrate        S1′ 4;    -   ii′) heating the adhesive layer 3 of the sealing device 1 which        faces the substrate S1′ 4, preferably to a temperature of 80 to        600° C.;    -   iii′) heating the adhesive layer 3 of the sealing device 1 which        faces away from the substrate S1′ 4, preferably to a temperature        of 80 to 600° C.; and    -   iv′) applying a substrate S2′ 5 to the adhesive layer 3 of the        sealing device 1 which faces away from the substrate S1′ 4.

The substrate S1′ 4 preferably involves substrates as they weredescribed above as the suitable and preferred substrate S1. The methodis in particular suitable for sealing a substrate St and additionallybonding it to a substrate S2′ 5.

The substrate S2′ 5 is preferably composed of a material as thematerials that were described above as being suitable and preferred forthe substrate S1.

Advantageous application and heating were described above.

A further aspect of the present invention relates to a method forsealing a substrate S1″ 4, comprising the following steps:

-   -   i″) applying a sealing device 1, as it is described above, to a        substrate S1″ 4, wherein the adhesive layer 3 faces the        substrate S1″ 4;    -   ii″) heating the adhesive layer 3 of the sealing device 1,        preferably to a temperature of 80 to 600° C.; and    -   iii″) applying a substrate S2″ 5 to the sealing layer 2 of the        sealing device 1.

The substrate S1″ 4 preferably involves substrates as they weredescribed above as the suitable and preferred substrate S1. The methodis in particular suitable for sealing a substrate St and additionallybonding it with a substrate S2″ 5, wherein the S2″ is able to form afirm bond with the sealing layer without the use of an adhesive promoteror an adhesive, in particular if the substrate S2″ 5 has a temperatureof 80 to 600° C. when it is applied to the sealing layer.

It is therefore advantageous if the substrate S2″ 5 has a temperature of80 to 600° C. when it is applied.

The substrate S2″ 5 is preferably asphalt. The application of asubstrate S2″ preferably involves liquid asphalt having a temperature of80 to 600° C.

Advantageous application and heating with respect to step i″) and stepii″) were described above.

A further aspect of the present invention relates to a method forsealing a substrate S1′″ 4 and a substrate S2′″ 5, comprising thefollowing steps:

-   -   i′″) applying a sealing device 1, as it is described above, to a        substrate S1′″ 4 and to a substrate S2′″ 5, wherein the adhesive        layer 3 faces the substrate S1′″ 4 and the substrate S2′″ 5; and    -   ii′″) heating the adhesive layer 3 of the sealing device 1,        preferably to a temperature of 80 to 600° C.

The substrate S1′″ 4 and the substrate S2′″ 5 are preferably structuralor civil engineering structures, the contact surface of which, oroptionally the intermediate space of which between the two substrates,is to be sealed. The substrate S1′″ can be concrete, for example, andthe substrate can be a pipe introduced into the substrate S2′″.

The sealing device 1 here fulfills the function of sealing

-   -   penetrating elements, such as rebars, cables and the like;    -   transitions between different shaped parts, such as between        concrete and steel components; and    -   expansion and construction joints, both in the case of        site-mixed concrete and in the case of construction by means of        prefabricated units.

Moreover, the substrate S1′″ and S2′″ can be mutually facing shapedconcrete bodies. The sealing device 1 here fulfills the function of awaterstop. The sealing device 1 can also have a shape and features asthey are known for waterstops to a person skilled in the art.

The material of the substrate S1′″ is in particular a mineral bindingagent such as concrete or gypsum, and most preferably the material isconcrete, in particular concrete. The material of the substrate S2′″ ispreferably metal or a metal alloy, or the material of the substrate S2′″is a mineral binding agent such as concrete or gypsum, in particularconcrete.

Advantageous application and heating with respect to step i′″) and stepii′″) were described above.

A further aspect of the present invention relates to the use of thesealing device 1 described in detail above for sealing bases.

The sealing device is typically used as a prefabricated membrane. Inthis case, the sealing device is preferably produced in the form ofsheeting by way of an industrial process and is preferably used in theform of a sealing device unwound from a roll at the construction site.However, the sealing device can also be used in the form of stripshaving a width of typically 1 to 20 cm, for example so as to sealconnecting points between two roofing membranes. Moreover, the sealingdevice can also be present and used in the form of planar bodies forrepairing damaged locations in seals, for example roofing membranes.

A preferred use of the sealing device 1 is thus a use for sealingstructural and civil engineering projects, in particular of roofs andfloors, against moisture.

A further aspect of the present invention relates to a method forproducing a sealing device 1, as it was described above in detail,wherein the sealing layer 2 and/or the adhesive layer 3 are produced byway of calendering and/or extrusion and/or co-extrusion and/orlamination.

The sealing layer 2 is preferably bonded to the adhesive layer 3 by wayof calendering and/or co-extrusion. The sealing device 1 can moreover beproduced as endless material and rolled to form rolls, for example.

It can further be advantageous if portions of the sealing layer 2 arefoamed during production, wherein the above-described foamed portions ofthe sealing layer 2 a are obtained. This is typically achieved by way ofphysical and/or chemical expanding agents, which are optionally presentin the sealing layer 2.

In a further aspect, the present invention relates to a shaped body,wherein the shaped body is firmly bonded to the adhesive layer 3 of thesealing device 1 by prior heating of the adhesive layer 3. The shapedbody is typically a structural or civil engineering structure. The term“shaped body” denotes an object having a three-dimensional expansion.

For example, FIG. 6 shows a shaped body composed of a substrate S1,which is bonded to the sealing layer 2 by way of the adhesive layer 3 a.The shaped body is preferably a prefabricated unit, which isindustrially produced. Industrial production allows more controlled heatinput into the adhesive layer than is possible at a construction site,for example. It can therefore be advantageous to dispense with a foamedportion 2 a of the sealing layer. Such shaped bodies can be sealedprefabricated elements for tunnels, water pipes, sewers, flooring andthe like, for example.

For example, FIG. 7 shows a shaped body composed of a substrate S1 4,which is bonded to the sealing layer 2 by way of the adhesive layer 3 a.The sealing layer comprises a foamed portion 2 a. Such shaped bodies canbe sealed roofs and floors, for example, in particular such made ofconcrete.

For example, FIG. 8 shows a shaped body composed of a substrate S1 4,which is bonded to the sealing layer 2 by way of a first adhesive layer3 a. The sealing layer comprises a foamed portion 2 a. A substrate S2 5is bonded to a second foamed portion 2 b of the sealing layer 2 by wayof a further adhesive layer 3 a.

For example, FIG. 9 shows a shaped body composed of a substrate S1 4,which is bonded to the sealing layer 2 by way of a first adhesive layer3 a. The sealing layer comprises a foamed portion 2 a. A substrate S2 5is bonded directly to the sealing layer 2. Such shaped bodies can be aroadway structure, for example, in which the concrete substructure(substrate S1) is sealed with the aid of the sealing device and to whichthe asphalt (substrate S2) is applied.

For example, FIG. 10 shows a shaped body composed of a substrate S1 4and a substrate S2 5, which are bonded to the sealing layer 2 by way ofthe adhesive layer 3 a. The sealing layer comprises a foamed portion 2a. Such shaped bodies can be sealed floors, for example, in particularsuch made of concrete. The sealing device is a waterstop, for example.

For example, FIG. 11 shows a shaped body composed of a substrate S1 4and a substrate S2 5, which are bonded to the sealing layer 2 by way ofthe adhesive layer 3 a. The sealing layer comprises a foamed portion 2a. Such shaped bodies can be sealed penetrating elements or transitionsbetween different substrates, for example. S1 is a floor, for example,in particular one made of concrete, and substrate S2 is a pipe made ofmetal or a metal alloy, penetrating the floor.

LIST OF REFERENCE NUMERALS

-   1 sealing device-   2 sealing layer-   2 a foamed portion of the sealing layer-   2 b foamed portion of the sealing layer-   3 adhesive layer-   3 a adhesive layer after heating-   4 substrate S1-   5 substrate S2-   6 heat source, or direction of the heat that is given off,    proceeding from the heat source-   9 carrier layer-   10 topcoat

EXAMPLES Experiments with Concrete Specimen

Production of Adhesive Layers:

Blends made of the ethylene-vinyl acetate copolymer P2, optionally thepolymer P3 and optionally azodicarbonamide were extruded on aco-rotating twin-screw extruder made by OMC (temperature 110° C.,rotational screw speed 200 revolutions/minute).

Production of the Test Specimen:

Test membranes were produced by first enclosing a reinforcing glassnonwoven having a thickness of 0.2 mm with two layers made of theabove-described adhesive layer, each having a thickness of 0.8 mm, byway of compression molding at 110° C. for 1 minute.

If the adhesive layers that were used did not include anyazodicarbonamide, the test membrane was heated to a temperature of 200°C. by placing it onto a polytetrafluoroethylene panel having such atemperature. Once this temperature was reached, a concrete test specimen(12×70 mm, height 25 mm; Rocholl, cut according to ISO 13640, method 1)was placed on the heated test membrane, additionally weighted with aweight of an additional 150 g and left in place for 2 minutes. The testspecimen thus obtained was then removed from the polytetrafluoroethylenepanel and allowed to cool to room temperature.

If the adhesive layers that were used included azodicarbonamide, thetest membrane was placed onto a polytetrafluoroethylene panel and heatedfor one minute with an industrial hot blow dryer from a distance of 10cm. Thereafter, a concrete test specimen (12×70 mm, height 25 mm;Rocholl, cut according to ISO 13640, method 1) was placed on theactivated test membrane, additionally weighted with a weight of anadditional 150 g and left in place for 2 minutes. The test specimen thusobtained was then removed from the polytetrafluoroethylene panel andallowed to cool to room temperature.

Application of the Primer:

For the test series that used test bodies with primer, one side of theconcrete test specimen (12×70 mm, height 25 mm; Rocholl, cut accordingto ISO 13640, method 1) was treated in advance with an epoxy resinprimer (Sika Primer 210 in the examples of FIG. 18; Sikagard 186 in theexamples of FIG. 21; both from Sika Schweiz AG) in accordance with themanufacturer's instructions. The treated side was then placed on theheated test membrane.

Measurement of the Test Specimen:

90° peel tests (at 23° C. and 50% humidity) were carried out on the testspecimen that were obtained, using a tensile testing machine (Zwick), ata constant cross beam speed of 100 mm/min.

P2 P2-1 EVA copolymer (28% by weight vinyl acetate, MFI 3), Elvax 265,DuPont P2-2 EVA copolymer (18% by weight vinyl acetate, MFI 0.7), Elvax470, DuPont P2-3 EVA copolymer (12% by weight vinyl acetate, MFI 0.35),Elvax 670, DuPont P2-4 EVA copolymer (28% by weight vinyl acetate, MFI0.5), Elvax CM4875, DuPont P2-5 EVA copolymer (28% by weight vinylacetate, MFI 6), Elvax 260A, DuPont P3 P3 LDPE-MAH, Bynel 42E703, DuPontA Azo Azodicarbonamid, Unicell DL75N, Dongjin Semichem Co. OBSH4,4′-Oxybis benzenesulfony hydrazide (OBSH), Luvopor OB, Lehmann +VossDP Radikalspender, Dicumyl peroxide Prim Epoxidharz-Primer, Sika Primer210, Sika Schweiz AG Epoxy Bisphenol A-basiertes Epoxy-Festharz, GT7004, Huntsman

The term “MFI” in the present document shall be understood to mean themelt flow index, measured at 190° C./2.16 kg according to the ASTM D1238standard, indicated in g/10 min.

FIG. 12 shows 90° peel tests of adhesive layers composed of 95% byweight P2-5 and 5% by weight azodicarbonamide (Azo), and 5% by weight ofthe chemical inflation agent 4,4′-Oxybis benzenesulfony hydrazide(OBSH), and 5% by weight of the radical starter dicumyl peroxide (DP).

FIG. 13 shows 90° peel tests of adhesive layers composed of the amountsof azodicarbonamide indicated in FIG. 13 in % by weight, theethylene-vinyl acetate copolymer P2-1 accounts for the remainder of thecomposition. The results of the measurement series, in which theuntreated concrete test body was used, are marked “without primer.” Theresults of the measurement series in which concrete test bodiespretreated with epoxy primer were used are marked “with primer.”

FIG. 14 shows 90° peel tests of adhesive layers composed of the amountsof polymer P3 indicated in FIG. 14 in % by weight, and the indicatedamounts of azodicarbonamide in % by weight, the ethylene-vinyl acetatecopolymer P2-1 accounts for the remainder of the composition. Concretetest bodies pretreated with epoxy primer were used.

FIG. 15 shows 90° peel tests of adhesive layers composed ofethylene-vinyl acetate copolymer P2-1 as well as the amounts of polymerP3 indicated in FIG. 15, and the indicated amounts of azodicarbonamide(Azo), in % by weight. The results of FIG. 15 are shown in FIG. 16 asthe ratio of the % by weight of (Azo: P3). Untreated concrete testbodies were used.

FIG. 17 shows 90° peel tests of adhesive layers consisting ofethylene-vinyl acetate copolymer P2-1, 5% by weight azodicarbonamide(Azo) as well as the amounts of polymer P3 indicated in FIG. 17.Untreated concrete test bodies were used.

FIG. 18 shows 90° peel tests of adhesive layers composed of 5% by weightazodicarbonamide (Azo) and 95% by weight ethylene-vinyl acetatecopolymer P2-3 (VA content 12% by weight), and 95% by weightethylene-vinyl acetate copolymer P2-2 (VA content 18% by weight), and95% by weight ethylene-vinyl acetate copolymer P2-4 (VA content 28% byweight). The results of the measurement series in which untreatedconcrete test bodies were used, are marked “without primer.” The resultsof the measurement series in which concrete test bodies pretreated withepoxy resin were used are marked “with primer.”

FIG. 19 shows 90° peel tests with adhesive layers composed ofethylene-vinyl acetate copolymer P2-1, 10% by weight polymer P3 as wellas the amount of epoxy resin GT 7004 indicated in FIG. 19 (noazodicarbonamide).

FIG. 20 shows 90° peel tests of adhesive layers composed ofethylene-vinyl acetate copolymer P2-1, 10% by weight polymer P3, 5% byweight azodicarbonamide (Azo) as well as the amount of epoxy resin GT7004 indicated in FIG. 20.

FIG. 21 shows 90° peel tests of adhesive layers composed of ethylenevinyl acetate copolymer P2-1, 10% by weight polymer P3, 5% by weightazodicarbonamide (Azo) and the amount of epoxy resin GT 7004 shown inFIG. 21. Concrete test specimen were used in the peel tests of FIG. 21,which were treated in advance with an epoxy resin primer as describedabove.

Experiment for Heat Input into an Adhesive Layer:

The above-described adhesive layers were produced in two differentthicknesses, a thickness of 2 mm on the one hand and a thickness of 0.3mm on the other hand. Those mentioned first were placed directly onto abase (concrete); on those mentioned second, the adhesive layer wasbonded with a foam layer measuring 1.7 mm thick and having a density ofapproximately 0.5 g/cm³ by way of a hot press before they were placed(with the foam layer facing the base) onto the base (concrete).Thereafter, the surface of the adhesive layers facing away from the basewas heated by way of an IR heater (KRELUS, output P=4.3 kW, radiatorfield 24 cm×56 cm) at a distance of 8 cm. The adhesive layers comprisinga foam layer behind the adhesive layer were activated twice as quickly.Moreover, a change in color was discernible in all activated adhesivelayers as compared to the non-activated state.

Adhesive Tests on Different Substrates:

Preparation of the Test Membranes:

An adhesive layer was prepared consisting of:

Celogen AZ 130, 9% by weight,

Zinc oxide, 3% by weight,

Bynel CXA 42E703, 13% by weight,

EVA with a VA content of 12%, 75% by weight,

and coextruded together with a layer of foamed EVA (VA content 14%, foamdensity approximately 0.5 g/cm³) on a concurrent twin-screw extruder(combing, L/D=44:1) of the company Berstorff (Germany) according to thefollowing extruder parameters and at an extruder number of revolutionsof 130 rpm.

Extrusion parameters Area T1 T2 T3 T4 T5 T6 T7 T8 T9 Temp [° C.] 30 5082 105 113 120 120 120 105

The thickness of the adhesive layer was approximately 0.4 mm, thethickness of the foam layer was approximately 1.8 mm. The test membranecontained furthermore a reinforcing glass nonwoven, an additionalunfoamed sealing layer of approximately 0.9 mm as well as a topcoat of0.3 mm. The width of the membrane from the extruder on was approximately30 cm.

Sample Preparation:

Strips of the test membranes having the dimensions 80 cm×30 cm×3.4 mmwere produced and heated at a rate of approximately 1 m/min with aheating gun (width approximately 25 cm, power approximately 40 kW,distance of 10 cm from adhesive layer), and pressed immediately withcontact pressure (pressing roller of 35 kg per 25 cm width) onto thesubstrate. The test body was stirred at standard atmospheric conditions(23° C./50% relative humidity) for 1 day. Subsequently, a 50-mm widetest strip was cut into the membrane and the peel strength wasdetermined by way of a dynamometer (hand peel test) or on a Zwickdynamic testing machine (machine peel test) at a peeling angle of 90°.

Substrate Adhesion with hand peel test Concrete ++ Stoneware (fine) topside + Stoneware back side ++ Stoneware back side ++ Ytong (porousconcrete) + ++ = >200 N/5 cm + = >100 N/5 cm, <200 N/5 cm

Adhesion with Substrate machine peel test Concrete without primer 300N/5 cm Wood, oriented strand board (OSB) 180 N/5 cm without primer Wood,oriented strand board (OSB) with 500 N/5 cm Sikagard 186 Zinc sheetwithout primer 400 N/5 cm Zinc sheet with Sikagard 186 400 N/5 cm

Epoxy resin primer, Sikagard-186, Sika Schweiz AG, was mixed beforehandaccording to the processing guidelines of the manufacturer (Comp. A:Comp. B=4:1) applied using rollers onto the corresponding substrate, andthen cured for 7 days.

The invention claimed is:
 1. A sealing device comprising: a sealinglayer comprising a thermoplastic polymer; and an adhesive layercomprising: at least one ethylene-vinyl acetate copolymer; and anazodicarbonamide; wherein the adhesive layer comprises from 0 to 0.5 wt.% of an epoxy resin, based on the total weight of the adhesive layer. 2.The sealing device according to claim 1, wherein the ethylene-vinylacetate copolymer comprises from about 25 wt. % to about 30 wt. % vinylacetate.
 3. The sealing device of claim 1, wherein the azodicarbonamideis present from about 0.5 wt. % to about 2 wt. %, based upon a totalweight of the ethylene-vinyl acetate copolymer and the azodicarbonamide.4. The sealing device of claim 1, wherein the azodicarbonamide ispresent from about 4 wt. % to about 8 wt. % based upon a total weight ofthe ethylene-vinyl acetate copolymer and the azodicarbonamide.
 5. Thesealing device of claim 1, wherein the ethylene-vinyl acetate copolymercomprises about 7 wt. % to about 30 wt. % vinyl acetate.
 6. The sealingdevice of claim 1, wherein the azodicarbonamide is present from about0.1 wt. % to about 15 wt. % based upon a total weight of theethylene-vinyl acetate copolymer and the azodicarbonamide.
 7. Thesealing device of claim 1, wherein the azodicarbonamide is present fromabout 2 wt. % to about 10 wt. % based upon a total weight of theethylene-vinyl acetate copolymer and the azodicarbonamide.
 8. Thesealing of claim 1, wherein the adhesive layer further comprises apolymer selected from the group consisting of a maleic acidanhydride-functionalized polyethylene and a maleic acidanhydride-functionalized copolymer made of ethylene and vinyl acetate.9. The sealing device of claim 8, wherein the polymer is present fromabout 4 wt. % to about 17 wt. %, and the azodicarbonamide is presentfrom about 2 wt. % to about 6 wt. % based upon a total weight ofethylene-vinyl acetate copolymer, polymer, and azodicarbonamide.
 10. Thesealing of claim 8, wherein the polymer is a maleic acidanhydride-functionalized polyethylene that comprises maleic acidanhydride-functionalized low density polyethylene or maleic acidanhydride-functionalized high density polyethylene.
 11. The sealing ofclaim 8, wherein the polymer is a maleic acid anhydride-functionalizedcopolymer comprising ethylene and vinyl acetate.
 12. The sealing deviceof claim 1, wherein the adhesive layer is free of epoxy resin.
 13. Thesealing device of claim 1, wherein the sealing layer comprises a foamedportion on a side facing the adhesive layer.
 14. The sealing device ofclaim 1, wherein the adhesive layer is tack-free at 23° C.
 15. A methodfor sealing a substrate, the method comprising: applying the sealingdevice of claim 1 to the substrate, wherein the adhesive layer faces thesubstrate; and heating the adhesive layer.
 16. The method of claim 15,wherein the heating comprises heating to a temperature of about 80° C.to about 600° C.
 17. The method of claim 15 further comprising applyinga second substrate to the sealing layer after heating the adhesivelayer.
 18. The method according to claim 17, wherein the secondsubstrate is asphalt.